Saturday, November 22, 2008

Goalies Always Get the Blame

Are NHL teams good at evaluating goalies independent of their team context? I think there is a lot of evidence that they certainly aren't perfect.

Take, for example, this information that I collected on the number of goalies each team has used in the last 10 years (since 1998-99). What stat is the best predictor of the number of goalies? Turns out it is GAA. Most observers would agree that GAA is strongly team-influenced, especially for goalies who play on very weak teams. Of the 10 best teams in GAA, only Ottawa and Philadelphia used more than 11 goalies. Of the 15 worst teams, everyone except Columbus used more than 11 goalies, and some of the teams used 20 or more.

Some of this effect is legitimately a result of goalie quality, but the fact that so many different goalies failed to make an impact on the league's weakest teams shows how tough it was to play there. It also shows how much more stable the goaltending situation tends to be on a top defensive team, and why goalies who come into the league on one of those teams have a much better chance at staying in that position for a while.

Here is the list of teams with GAA and number of goalies they have employed in the last decade:

Whoops, good catch, I got the numbers from Hockey-Reference but for a few of the teams I was accidentally counting single seasons, not combined seasons (like Pittsburgh, Phoenix, etc.). I have edited the post to reflect the actual numbers. The overall point still stands, but the relationship is not as strong.

oh, for heaven's sake, CG, surely the appearance of the same name multiple times should've been enough to tip you off?

Another flaw with this argument might be - goalie carousel or not, is someone who plays fewer than 10 games with a franchise really affecting, or being affected by, anything? (excluding them all the number of Pens goalies drops to 10. Just 3 more than Jersey, and no one will say Pittsburgh was renowed for its defense during that time.)

I'm using Pittsburgh as an example, of course, but I think you'd be more accurately serving your argument by focusing on the percentage distribution of total games played within a team. If Marty Brodeur plays 500 games (90+%), does it matter if he has 5 backups or 10 playing the little that remains? Doesn't that mean something different than if another team has 5 guys playing 100 games each over the same timespan? (which I believe was your original point, but I don't think it's so much about number of goaltenders, as *time*.)

About Me

I'm Philip Myrland, goalie stats blogger since 2007 and former writer for Hockey Prospectus. I call myself a contrarian because I rely mainly on stats-based analysis, think large sample sizes are more important than "big saves" and prefer to rank goalies based on save percentage rather than team success. In other words, pretty much the mainstream views of the hockey analytics community, but I've grown attached to the handle and plan to keep it as long as broadcasters everywhere keep bringing up GAA and wins. If you have any questions or comments contact me by email (contrariangoaltender@gmail.com). You can also follow me on Twitter (@tcghockey).